Spatial Contamination and Potential Ecological Risk Assessment of Heavy Metals in Farmland Soil around Nonferrous Metal Smeltery in North China

Nonferrous metallurgy is an important source of heavy metal in the environment and consequently poses potential risks to ecosystems. The impact of smelting on the surrounding envi-ronment is a concern. In this work, the content levels of selected heavy metals—chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), and arsenic (As)—were investigated separately in soil samples collected around two nonferrous metal smelteries using inductively coupled plasma mass spectrometry (ICP-MS). The spatial distribution characteristics of soil metal pollutants was studied by ArcGIS methods and the potential ecological risks were assessed by the Hakanson potential eco-logical hazard index. The results show that soils were heavily polluted by Cr, Ni, Cu, Zn, Cd, Pb, and As. Their mean contents in soil around Smeltery A were 88, 62, 103, 1200, 1.4, 146, and 69 mg/kg, respectively, and those around Smeltery B were 86, 59, 83, 117, 0.53, 57, and 65 mg/kg, respectively. Their contents were obviously higher than the background values of soil Cr (68 mg/kg), Ni (31 mg/kg), Cu (22 mg/kg), Zn (78 mg/kg), Cd (0.09 mg/kg), Pb (22 mg/kg), and As (14 mg/kg). The distribution pattern in soil and risk assessment results show that the pollution surrounding the two smelteries reached intense and moderate ecological hazard and that the contribution of Cd and As was up to 87.05% and 82.59%, respectively. These results suggest that metal smelting makes a considerable contribution to soil pollution.

A New Inductive Debris Sensor Based on Dual-Excitation Coils and Dual-Sensing Coils for Online Debris Monitoring

Lubricants are of key importance for mechanical processing, and exist in nearly every mechanical system. When the equipment is in operation, debris particles will be generated in mechanical lubricants. The detection of debris particles can indicate the wear degree of machinery components, and provide prognosis warning for the system before the fault occurs. In this work, a novel type of inductive debris sensor consisting of two excitation coils and two sensing coils is proposed for online debris monitoring. The developed sensor was proven to be of high sensitivity through experimental verification. The testing results show that, using the designed sensor, ferrous metal debris with a size of 115 μm and nonferrous metal debris with a size of 313 μm in a pipe with an inner diameter of 12.7 mm can be effectively detected. Moreover, the proposed inductive debris sensor structure has better sensitivity at higher throughput and its design provides a useful insight into the development of high-quality sensors with superior performances.

Unlocking the Sustainable Development Path of China’s Nonferrous Metal Industry Based on Collaborative Innovation

The sustainable development of an industry is an important topic of technological innovation. To unlock the path dependence of industrial development, it is critical to identify the evolution law of the industrial collaborative innovation network. Taking China’s nonferrous metal industry as an example, this paper establishes two collaborative innovation networks from the time and space dimensions, respectively. The networks cover both the macroenvironment and the microinnovative subjects of the industry and fully consider the collaborative relationships between these subjects. Through multilevel and multidimensional analysis, the authors drew the following conclusions: the macropolicies and technology paradigm can create a window of opportunity for the industry, which directly drives the breeding of new industries and the transformation and upgrading of traditional industries; the interaction between the macroenvironment and microinnovative subjects leads to the differentiation of the industrial innovation path; the provinces can enter the first echelon of interprovincial innovation collaboration and realize sustainable development of the industry through the unlocking path, which consists of path continuation, path expansion, path implantation, and path diversification.

Dispersed Gold and Associated Disseminated Mineralization of Leucogranites of the Dukat Ore Field as Indicators of the Generation Conditions of Magmatogene Gold-Bearing Fluids

—We present data on dispersed gold and associated disseminated mineralization of leucogranites controlling the location of the Dukat epithermal Au–Ag deposit. The data suggest the formation and burial of small portions of oversaturated gold-bearing fluids in hypabyssal magmatic bodies. The lower (relative to silver) contents of gold in the deposit ores and the high Ag/Au ratios (350–550) are due to the limited occurrence of oxidized gold-bearing fractions of magmatogene fluids. This limitation is explained by the active interaction of late magmatic portions of fluids and the material of the host carbonaceous volcanosedimentary unit and by the formation of an environment favorable for the concentration, migration, and deposition of manganese, silver, and nonferrous-metal compounds.

An Up-to-Date Review on Industrially Significant Inhibitors for Corrosion Control of Zinc

Zinc, an important nonferrous metal, is the fourth most used metal in the world. It has innumerable uses in industrial as well as in other segments. The primary utility of zinc is in galvanization and as an anode in the battery. Steel coated with zinc, which is known as galvanized steel, is widely used in industries. Even though zinc protects many metals from undergoing corrosion, by itself, it undergoes corrosion in several acidic, alkaline, and neutral environments. The corrosion behavior of zinc is significant in all industries where it is utilized either directly or indirectly in the form of a sacrificial coating. In-depth analysis of the reported literature indicated that corrosion attenuation of zinc in acidic and alkaline medium was studied by many researchers, and various classes of inhibitors were tried under varying experimental conditions. Most inhibitors can be amalgamated as excellent inhibitors with an inhibition efficiency of 80–90%. Even though this is a subject of intense research, systematic documentation on the same is not available in the literature. This review consolidates research work on corrosion and inhibition studies of zinc and galvanized steel over a period of three decades.